Process of desulfurizing petroleum-oils



E. B. COBB.

PROCESS 0F DESULFURIZING PETROLEUM OILS.

APPLICATION FILED MAR. 13, I919- OQ. W m 5 R m Wm H w Nm w A as ..l. W O w, 4 Aw. .1 7% .j q] @j mm v W m a -a. 2 w 7 1 E. B. COBB.

PROCESS OF DESULFURIZING PETROLEUM .OILS.

APPLICATION FILED MAR. 13, 1919.

1,357,225. Patented Nov. 2, 1920.

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WITNESS: I I N V EN TOR ww h, B

' ATTORNEYS nish or blacken the copper or silver.

"UNITED STATES PATENT OFFICE.

ERNEST B. COBB, 0F JERSEY CITY, NEW JERSEY, ASSIGNOR T'O STANDARD OIL COMPANY, A CORPORATION OF NEW JERSEY.

PROCESS OF DESULFURIZING PETROIiEUlVI-OILS.

To all whom it may concern:

Be it known that T, ERNEST B. COBB, a

citizen of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Processes of Desulfurizing Petroleum-Oils, of which the following is a specification. I

My invention relates toinew and useful improvements in processes for the removal of elementary sulfur from petroleum oils. My present application is a division, in part, of my prior application, Serial No. 50,177, which was filed in the Patent Office on or about September 11, 1915, Patent No. 1,300,-

816, April 15, 1919. By elementary sulfur treatment of the oils and other processes of refining and chemical treatment' The presence of elementary sulfur in petroleum oils may be ascertained by first testing the oil by any of the well-known tests for sulfureted hydrogen (H 8) and removing the same if any be present by any of the wellknown processes for this purpose, after which a piece of bright copper or silver is immersed in the oil freed of sulfureted hydrogen (H S) and theo'il heated; if any elementary sulfur is present it will act to e removal of sulfureted hydrogen from the test oil is a necessary preliminary because it also darkens copper and silver. But in the treatment of the main body of oil, as hereinafter described, it is unnecessary to removeth'e sulfureted hydrogen by preliminary treatment.

T have discovered that elementary sulfur existing in petroleum oils, either primarily, or as the result of treatments, or'reactions, with other compounds, or elements, may be removed by treatment with sulfids of the alkaline earths. By sulfids I refer particularly, although not necessarily, or by way of limitation, to monosulfids-that is to say, for example, calcium sulfid (c-as), etc.

It is well known that higher sulfids of these metals, such as calcium, exist, and the Specification of Letters Patent.

chemical action in using sulfids thereof, as

Patented Nov. 2, 1920,

Application filed March 13, 3.919. Serial No. 282,288.

contemplated by my invention, is to cause removal of the elementary sulfur apparently by simple addition, the sulfur combining with the low sulfids .of the alkaline earth metal to produce higher sulfids.

By sulfids of the alkaline earth metals, I mean sulfids of the alkaline earth metal group, but in practice I preferably use sulfids of lime, although I do not necessarily exclude any of the sulfids of the alkaline earth metal group.

My invention may be carried out either by filtering the oil through an alkaline earth sulfid under proper conditions, or by agitating the sulfid with the oil.

In the drawings in which like reference numerals indicate like parts, Figures 1 and 2 illustrate an apparatus for carrying out the filtering process with alkaline earth sulfids, Fig. 1 being a side elevation, and Fig.

2 a section of the lower portion of the tank, and Fig. 3 is a side View, partially broken away, of an apparatus for carryin out the agitation process with alkalineearth sulfids.

In Figs. 1 and 2 I show an apparatus for filtering the 'oil through a sulfid of an-alkaline earth metaL and this is the-preferred method of carrying out my invention. This apparatus includes a vertically disposed cylinder or tank 30, adapted to contain the Oil to be desulfurized, a feed pipe 31, entering the upper portion of the cylinder to feed the oil to the latter. The cylinder is provided with an upper head 32, and a lower head 33, the former being provided with a manhole 34. The lower head is provided with a central opening 35 discharging into a neck 36, bolted to said head, and closed at its lowerend by a removable cover plate 37. The body of the neck is of less diameter than the opening 35, for a purpose to be described, and is provided with an external flange or shell 38 forming with said neck an annular passage 39, having an inclined bottom 40, said passage being accessible to the interior of the cylinder through the annular space 41 afforded between the upper portion of the neck and the edge of the opening 35. The upper edge portion of the flange 38 provides convenient means by which the neck may be bolted to the cylinder. A suitable outlet pipe 39 leads from the passage 39.

The bottom head of the cylinder is provided witha false bottom consisting of a layer of wire mesh 42,

the mesh and the canvas covering are cut. away at the center, as shown, the inner edge of the mesh preferably terminating slightly short of the annular passage 39, while the inner edge of the canvas is carried over said passage and securedto said neck by a clamping ring and bolts 46.

The wall of the cylinder is provided with an inwardly projecting annular flange 47 overlying the outer edges of the canvas and wire mesh layers, the space between the said flange and the canvas being packed with cotton or wool waste packing, as at 48. 'Adjacent its lower end portion the cylinder is provided with a manhole 49 for a purpose to be presently set forth. v

In carrying out my process, filtering the oil through sulfids of the alkaline earth group, I preferably proceed as follows:

800 pounds of freshly burned lime are placed preferably in an open pan or receptacle, into which is poured a mixture of 600 x pounds of commercial sulfid of soda and 50 gallons-(417 pounds) of water. As the lime' slakes there is a decomposition of the sulfid of soda, thereby forming sulfid of lime and caustic soda. Upon the termination of the slaking action the material, 6. e. the sulfid of lime and caustic soda, should be granular and somewhat coarse. The material is then placed in the chamber of the tank 30 and spread evenly over the false bottom thereof to the proper height, as indicated by the dotted line in Fig. 1 of the drawings] When the material is packed in the tank the impure oil to be desulfurized is pumped in at the top of the tank through the pipe 31, and is {permitted to percolate down through the lter-like bed of sulfid of lime. The oil in passing through the sulfid of lime is completely desulfurized by reaction of the sulfur with a sulfid of lime by simple addition to produce higher sulfids, as has been previously set forth. The degree of desulfurization maybe determined by the copper test described on samples of the oil taken from the outlet pipe 39"-. The purification in this case may be continued until test samples show no blackening of copper when tested as described, whereupon the exhausted sulfid is removed and the tank is recharged with a fresh supply of sulfid.

The filtering method above described ef-' fects contact between the oil and solid sulfid as distinguished from contact of the oil and liquid sulfid in the process described in.

my parent application, Serial No. 50,177. The two methods are largely interchangevides for a systematic use of the active agent; that is, as the operation progresses the raw 'oil comes in contact with partially exhausted sulfid first, and on passing to the bottom of the filter it meets sulfid of a less and less degree of exhaustion.

It will, of course, be understood that the alkaline earth sulfid may be prepared in any desired manner, and that the process outlined above is, therefore, only illustrative. A sulfid of lime'may, for'example, be prepared in the following manner: 800 pounds of freshly burned lime may be placed in an open pan or receptacle into which is poured 50 gallons of water, the amount of Water added being just 'suflicient to leave the lime in the proper physical condition, neither dusty nor pasty. The material is then introduced into the tank 30 and spread evenly over the false bottom. Sulfureted hydrogen is then introduced into the bottom of the tank which converts the solid lime into calcium monosulfid. The remainder of. the process may then be carried out in precisely the same manner aswhen the calcium sulfid is added to the tank.

In Fig. 3. I have shown an apparatus for carrying out the process where the alkaline earth sulfid is agitated with the oil to be treated. In the apparatus there shown, 1 designates a cylinder or receptacle adapted to receive the oil to be treated and having a conical bottom 2 and a dome-shaped t0p.. or

cover 3, which is preferably provided with doors 50. The conical shaped bottom 2 is provided at its apex with an outlet pipe 4 having a valve 5 at its lowermost portion, through which pipe the contents of the cylinder may be flowed when the valve isopen. as will be hereinafter described. A steam inlet pipe- 18 enters the tank through the cover 3 and is provided with a depending outlet portion 19, by means of which live steam may be admitted to the interior of the cylinder, an air inlet pipe 20 being connected with pipe 18 and provided with a valve 21, for a purpose to pipe 18 may-be provided with a valve 22 for controlling the flow'of steam from the pipe to the interior of the cylinder, said pipe being connected with the pipe18 between the valve 22 and the outlet end of said. pipe 18. Also connected to the'steam pipe 18 is a'pipe 23 leading to a closed heating coil 24, of any suitable form, located within the botbe presently described. The i tom portion of the cylinder, said coil being mamas of the steam coil, which is "indicated by the character 26, is provided with a valve 26 A second heating coil v24: is preferably provided having a valve 24 at its free end.

The inlet pipe for feeding the oil to be treated to the cylinder is shown at 27, the said pipe entering the cylinder adjacent the upper portion thereof and extending to a point preferably within the area of the coneshaped bottom. The treated oil may be withdrawn from the cylinder through an outlet pipe 28, controlled by a valve 29, said pipe being located at a point on the bottom of the cone-shaped bottom, which will be above the solid material which settles from the oil during the process. The pipe preferably communicates within the cylinder with an adjustable swing pipe 28, which will be adjusted in accordance with the depth of the solid material formed in the bottom of the tank.

I do not desire to be limited in any way to an apparatus such as described, having only described the same in detail so as to insure an adequate understanding of the process embodying my invention.

In carrying out the-process with the apparatus illustrated in Fig. 3, the alkaline earth sulfid may be prepared in accordance with the method outlined in connection with the apparatus illustrated in Figs. 1 and 2, and after the oil has been placed in the tank the alkaline earth sulfid may be introduced to the oil through the doors 50. Steam is now introduced through the pipes 23, 24% and 24 in order to warm the oil, the valves at the free ends of the pipes 24 and 24 being open sufiiciently to carry away the condensed water. The oil is heated to a temperature above the condensing point of water, from 212 F. to 300 F. Dry steam is then introduced through the pipe 19 in order to agitate the oil, and then the sulfid of the alkaline earth is introduced through the top of the agitator to the oil. The agitation is continued untila specimen of the oil, when the solid material is settled out, and when the oil is submitted to the copper test, shows that the sample is free from sulfur. If continued agitation does not eliminate all the sulfur, more sulfid 0f the alkaline earth must be employed. The length of time required for carrying out the process will, of course, depend upon the amount of oil under treatment. With a tank containing 100 barrels of oil, I have found that the treatment can usually be carried out in from one to three hours. When the elementary sulfur has been entirely removed, the steam is shut off and the oil allowed to settle. This settling may require about an hour. When the settling is completed, the oil is drawn ofi' through the adjustable swlng pipe 28, and the spent material is washed from the bottom of the tank through the pipe 4:, and the the process under alkaline conditions for the.

reason that the alkali neutralizes any acid bodies left in the oil from previous refining processes, and because the material appears to be more active in its action upon the elementary sulfur contained in the oil when the material is alkaline.

It is to be understood, however, that under certain conditions, the process may be successfully carried out when the liquid is not alkaline, and my invention, therefore, is not limited to carrying out the process under alkaline conditions.

It is also to be understood, that in case objectionable odor or taste remain in the oil after the treatment described above, a suitable washing process may be carried out. In the agitation process shown in Fig. 3, this washing process may be carried out either by injecting steam into the oil through the pipe 19, or the oil may be washed with water in a well known manner. The apparatus shown in Figs. 1 and 2 does not lend itself to the washing process, and in case the oil under treatment in the filtering process needs to be Washed, the oil should be transferred to a suitable receptacle where the washing process may be carried out. Inasmuch as the treatment above described. however, will ordinarily produce oil that requires no washing, and since the washing process is one that is well understood in the art, I have not shown the apparatus necessary for carrying out this washing process.

What I claim and desire to secure by Letters Patent of the United States is:

1. The process of removing elementary sulfur from petroleum oil, which consists in subjecting said oil to an alkaline earth sulfid.

2. The process of removing elementary sulfur from petroleum, oil, which consists in subjecting said oil to an alkaline earth sulfid,

and continuing the treatment until the treatsulfur iirom petroleum oil, which consists in subjecting said oil to analkaline earth sulfid under alkaline conditions.

5. The process of removing elementary 5 sulfur from petroleum oil, which consists in filtering the oil through a body of an alkaline earth sulfid. Y

6. The process of removing" elementary sulfur from petroleum oil, which consists in 10 filtering the oil through a body of calcium sulfid.

7. The process of removing -elementary sulfur from petroleum oil, which consists in subjecting said oil to the action of calcium 8. The process of removing elementary sulfur from petroleum oil, which consists in filtering the oil through a body of an alkaline earth sulfid, and continuing the process until the treated oil ceases to have a dark- 20 ening effect on metallic copper.

9. The process of removing elementary sulfur from petroleum oil, which consists in subjecting said oil to a material formed from. the following materials in substan- 2-5 tially the following proportions: lime 800 pounds, sulfid of soda 500 pounds, and water 50 gallons.

In testimony whereof I have hereunto signed my name in the presence of two sub-V 30 scribing witnesses A ERNEST B, COBB.

Witnesses ADELE S. EBERHARDT, DANN L. WOOD. 

